Thanks a lot to all of you for your responses ! Much appreciated !
I cant tell precisely what are gonna be all of my future equipments. All I can say is that I'm going for a LPS dominated mixed reef and that I dont really plan on using a dosing pump.
I think both system would do an excellent job. I keep reading that Hydros controllers seem to be better build, but that the Apex compatibility is better for equipments of other companies... Tough choice, honestly.
What I can say is that general quality is important for me. I really dont know about customer service of neither company here in Canada.
Thanks again and please keep comments coming if you think of anything that might help me make a decision!
If build quality is important to you, I think you'd probably be disappointed with Apex. I was pretty surprised at how cheap and flimsy their stuff feels considering the price. The DOS was the only exception to this that I had.